標題: | Physicochemical and electrochemical properties of the (fluorosulfonyl) (trifluoromethylsulfonyl)amide ionic liquid for Na secondary batteries |
作者: | Yang, Huan Luo, Xu-Feng Matsumoto, Kazuhiko Chang, Jeng-Kuei Hagiwara, Rika 材料科學與工程學系 Department of Materials Science and Engineering |
關鍵字: | Na secondary batteries;Ionic liquids;(fluorosulfonyl)(trifluoromethylsulfonyl)amide;Hard carbon |
公開日期: | 15-九月-2020 |
摘要: | In this study, thermal, physical, and electrochemical properties of the ionic liquid electrolyte system, Na[FTA]-[C(3)C(1)pyrr][FTA], (FTA(-) = (fluorosulfonyl) (trifluoromethylsulfonyl)amide and C(3)C(1)pyrr(+) = N-methyl-N-pro-pylpyrrolidinium) have been investigated for Na secondary batteries. The asymmetric FTA. structure provides a wide liquid-phase temperature range, especially at low x(Na[FTA]) (x(Na[FTA]) = molar fraction of Na[FTA]) and low temperature range. Glass transition at 170-209 K is the only observed thermal behavior in the x(Na [FTA]) of 0.0-0.4. Temperature dependence of viscosity and ionic conductivity obeys the Vogel-Tammann-Fulcher equation, and the correlation between molar conductivity and viscosity follows the fractional Walden rule. The anodic potential limits are above 5 V vs. Na+/Na at 298 and 363 K. The noticeable effects of x(Na [FTA]) are observed in the electrochemical performance of Na metal and hard carbon electrodes. In both cases, a moderate concentration, x(Na[FTA]) of 0.2-0.3, enables favorable charge-discharge behavior. At 363 K, the discharge capacities of the hard carbon electrode at x(Na[FTA]) of 0.3 are 260 and 236 mAh g(-1) at the current densities of 20 and 200 mA g(-1), respectively. The optimum cycling performance occurs at x(Na[FTA]) = 0.3, providing satisfactory capacity retention and high average Coulombic efficiency. |
URI: | http://dx.doi.org/10.1016/j.jpowsour.2020.228406 http://hdl.handle.net/11536/155000 |
ISSN: | 0378-7753 |
DOI: | 10.1016/j.jpowsour.2020.228406 |
期刊: | JOURNAL OF POWER SOURCES |
Volume: | 470 |
起始頁: | 0 |
結束頁: | 0 |
顯示於類別: | 期刊論文 |